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XMM-Newton observation of the brightest X-ray flare detected so far from SgrA*

D. Porquet·P. Predehl·B. Aschenbach·N. Grosso·A. Goldwurm·P. Goldoni·R. S. Warwick·A. Decourchelle
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Abstract

We report the high S/N observation on October 3, 2002 with XMM-Newton of the brightest X-ray flare detected so far from SgrA* with a duration shorter than one hour (~ 2.7 ks). The light curve is almost symmetrical with respect to the peak flare, and no significant difference between the soft and hard X-ray range is detected. The overall flare spectrum is well represented by an absorbed power-law with a soft photon spectral index of Gamma=2.5+/-0.3, and a peak 2-10 keV luminosity of 3.6 (+0.3-0.4) x 10^35 erg/s, i.e. a factor 160 higher than the Sgr A* quiescent value. No significant spectral change during the flare is observed. This X-ray flare is very different from other bright flares reported so far: it is much brighter and softer. The present accurate determination of the flare characteristics challenge the current interpretation of the physical processes occuring inside the very close environment of SgrA* by bringing very strong constraints for the theoretical flare models.

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D. Porquet, P. Predehl, B. Aschenbach, N. Grosso, A. Goldwurm, P. Goldoni, R. S. Warwick, A. Decourchelle. 2003-07-07. XMM-Newton observation of the brightest X-ray flare detected so far from SgrA*. https://doi.org/10.1051/0004-6361%3A20030983

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